Engines, and particularly diesel engines, require fuel heaters during cold weather to prevent precipitation of wax from the fuel which tends to plug screens and fuel injectors. Heating of the fuel will correct this, but it is very easy to overheat the fuel, which gives it an abnormally low density which will have an effect on the fuel metering system.
The present invention overcomes these problems as the new heater includes a temperature control system having a fuel temperature-actuated valve means for bypassing either completely or partially the heated means in the heater from which the fuel is adapted to receive heat when such fuel heating is unnecessary. Because the operation of the valve is controlled by the temperature of the fuel in the heater, it is self-regulating to provide the proper amount of heat to the fuel.
The best prior art of which Applicants are aware consists of the following U.S. patents, none of which disclose the invention as claimed herein: Bay U.S. Pat. No. 2,670,933; Andersen U.S. Pat. No. 2,788,176; McGinnis U.S. Pat. No. 2,881,828; Moon U.S. Pat. No. 3,472,214; Markland U.S. Pat. No. 3,768,454; and Johnston U.S. Pat. No. 4,231,342.